Just This Once
by brokibrodinson
Summary: Tony Stark has caught the eye of Loki, god of mischief. Tony is in a happy relationship with Steve Rogers. Steve isn't averse to new things especially with a little magical prompting. Some dubcon I guess. Established Tony/Steve. Loki/Tony. Loki/Tony/Steve. Loki/Loki. Oneshot. Complete.


A/N: I accidentally a Loki/Tony/Steve oops. I blame my good friends on tumblr for encouraging this ridiculous thing. Not my best work but I haven't actually completed anything for at least a year now so this is what you get.

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Loki was restless. Restlessness suited him ill, for he was a patient creature both by nature and by habit. He had to be, for many of plans would take time to come to fruition.

As much as he was loath to admit it to himself, Loki wanted Tony Stark. It was a phase, nothing more, he knew. In the same way a child longs after a toy and then discards it after only a few plays, Loki wanted to play with Tony, see just how clever a mortal's mind could be (and to see how much he could twist him into his own creature).

He had been impressed, despite himself, by Stark's intellect and amused by his bold humour. It was a shame he was one of the troublesome 'Avengers' Loki mused.

Chaos and calamity would suit such a mischievous being well indeed.

Loki eventually gave into the urge to visit Tony Stark, reasoning that the sooner he rid himself of such ridiculous thoughts, the better.

Appearing in the Avengers Tower one evening, Loki found Tony pouring himself a drink at the bar. "Do you always drink this often?" he asked curiously.

Tony jumped, almost dropping the bottle he was holding before focusing on Loki. "What are you doing back here?" he demanded, still in slight shock.

"You still owe me that drink," Loki replied, smiling. "I was in the mood to collect."

"I don't share the good stuff with stray Norse gods" Tony stated calmly, placing the bottle safely back on the bar.

Loki was about to respond but instead promptly vanished.

Tony wondered why until Steve walked in, almost seconds later.

"Coming to bed, Tony?' he asked, yawning sleepily

Loki glared at the new arrival. He'd cast a simple spell of invisibility over himself – there was no benefit to the other Avengers knowing he was here. He doubted Tony would report his presence to Rogers anyway, especially as he would probably assume he had vanished.

"I'll be there in a sec" Tony replied, proving Loki right.

Steve raised an eyebrow at him, sighing at the glass in his hand, but made no comment. Tony knew he didn't approve of his drinking but there was no use nagging him. He walked back out, deciding to go to bed – Tony could join him when he pleased.

"Now I have you all to myself" Loki purred, his form reappearing once Steve had gone.

"What's that supposed to mean?" Tony asked suspiciously, not all that surprised by his reappearance.

"What do you think I mean?" Loki questioned in return. He stalked closer, relishing the look of worry that crossed Tony's face. It was not fear exactly. Just apprehension.

He seated himself at the bar, Tony continuing to watch him warily

"Still not going to pour me a drink?"

Tony laughed harshly "You've got to be kidding."

"Do parents no longer teach their children manners?" Loki muttered. "No matter, I never really enjoyed your Midgardian drinks anyway."

"Then why are you here?" Tony asked

"Because I hunger" Loki answered simply, eyes burning as he held Tony's gaze.

Tony snorted, finishing his drink and moving to leave, only to have his wrist caught in a strong grip.

"You're not getting away from me that easily" a voice hissed in his ear.

Tony was about to protest only to be silenced by a sudden demanding kiss, Loki's tongue leisurely exploring his mouth. He struggled, causing Loki to hold him closer, his other arm snaking around him to pull him flush against himself.

As soon as the kiss ended, Tony spat 'get the fuck off me" trying in vain to push Loki away.

Loki just smirked down at him, kissing him once more, then backing away, releasing his grip.

"One might wonder why you haven't called in reinforcements yet" he commented idly.

"I can take you" Tony snapped, his pride winning out over his common sense, "no need to wake the others up."

Loki grinned at Tony's words, "And here I thought I'd be taking _you_" he quipped.

He pulled a struggling Tony close again, intending to ravish him when Steve returned.

"Hey Tony, it's getting pretty late, you should-" Steve's voice trailed off and his eyes widened in shock at the sight in front of him.

Loki smiled devilishly at the shocked super soldier in the doorway. "Rogers, how nice of you to join us" he greeted him, not releasing Tony.

"Are you okay, Tony?" Steve asked worriedly, approaching Loki threateningly.

"I'm fine, can you just get him off me?" Tony hissed.

"I have a better idea" Loki said. "Why don't you join us, dear captain?"

"WHAT?" Steve and Tony both spluttered in unison.

"There is nothing _to_ join" Tony snapped, just as Steve asked "what is going on here?"

Steve was rendered speechless as he watched the god of mischief ravage his Tony's mouth.

At once he felt fury, horror and... arousal? _No._ _Absolutely not._

Loki, the sly bastard, sensed this and smirked over at him, face still inches away from Tony's.

"Come here, Rogers" he ordered, as Tony looked confusedly between Loki and Steve.

As though in a trance, Steve approached, telling himself he was just going to free Tony, of course he was, what else would be – _oh_. He shuddered as phantom hands wrapped around him, pulling him closer to the pair, some of them lingering in places he'd rather they wouldn't.

Or at least he knew he should rather they wouldn't but could feel himself coming undone under their care.

Loki released Tony's wrist and pulled Steve closer to pull him into a searing kiss.

Tony watched in rising horror. "What the fuck is happening" he demanded of Loki, "what have you done to him?"

"Why, nothing at all" Loki grinned, voice a lascivious drawl. "Have I, Rogers?"

"Steve?" Tony asked anxiously.

Steve had been blushing furiously ever since Loki had kissed him.

"Steve!" Tony tried again, voice urgent.

Steve looked up hesitantly, meeting Tony's eyes.

"No what, you're kidding me, snap out of it" Tony demanded. "Fix him" he growled, turning back to face Loki who still held him in a one-armed embrace against himself.

Loki just laughed softly, pulling Steve closer to Tony. "Just kiss him, Rogers, we don't have all night."

"What?" Tony snapped only to be silenced by soft lips on his as Steve kissed him. It was a gentle kiss, barely more than chaste until he felt a tentative tongue trace his lips.

Loki withdrew his arm as Tony practically melted under Steve's shy attentions.

Then Tony remembered himself, pushing Steve away carefully to glare at Loki.

"Get out."

Loki pretended to look hurt. "Throwing me out of my own party are you?"

"Yes," Tony replied harshly only to be stunned into silence as Steve went to stand beside Loki, Loki's arm curling around Steve's waist as he kissed him deeply.

"C'mon Tony, it's just this once" Steve pleaded once they broke apart for air.

"What the fuck, Steve?' Tony snapped, ignoring Steve's wince at his language. "This is Loki. LOKI. As in our enemy? Remember?"

Loki laughed, whispering something in Steve's ear that caused him to blush and bite his lip before saying "Really now, Tony, can't you just enjoy an opportunity when it presents itself?"

"No." Tony said flatly. "Come on, Steve, we're going to bed."

He made to walk out of the room only to have the doors slam in his face."Do you mind NOT turning my house against me?' he snapped at Loki.

Loki shrugged elegantly, wicked smile still in place.

A part of Tony itched to join Steve and Loki - they did look wonderful together, he mused. Dark and slender versus light and fair - the contrast was dazzling.

But this was _Loki_ the more logical part of his brain contended. He had to figure out what he'd done to Steve and then get him the hell out of there.

Tony decided to ignore that part - when did he ever listen to it anyway? – especially when he saw the way Loki's clever fingers were threatening to slip under Steve's clothing.

Filled with a sudden wave of protective possessiveness, he strode over angrily only to be met halfway by a clone of Loki's that appeared out of nowhere.

The clone blocked his path, grinning lecherously before pulling Tony into a brief kiss. Tony went pliant in the clone's arms, figuring he could take him by surprise and escape when he got the chance.

However once he let himself go it became very hard to concentrate, let alone fight back as the Loki-clone's arms tightened around him and kissed him again, this time more demanding.

He didn't realise how far he'd gotten into the kiss until his eyes snapped open as though from a trance as he heard Steve's familiar low moan from across the room.

Pushing the clone away and successfully extricating himself from it, he looked over to see Steve being pinned against the wall and being thoroughly ravished by the real Loki.

Tony hissed in a breath at the sight, turned on despite himself.

The Loki-clone watched amusedly as Tony approached the pair, raising an eyebrow as he whispered something into Loki's ear.

Loki looked at him in surprise, then released Steve and backed away, letting Tony take his place.

Steve opened his eyes as he felt Loki's ministrations cease, only to close them again and rest his head back against the wall with a gasp as Tony sucked at his throat, pressing his knee to Steve's arousal and rubbing softly.

Loki was watching all this take place with interest, only to feel a hand creep under his long coat and stroke him softly.

He whipped around in surprise to meet gleaming emerald eyes identical to his own. Loki was about to dismiss the clone in pure shock only to think to himself that he had most definitely done stranger things in his long life.

Instead, he pushed his clone to its knees, gazing down at it imperiously.

The clone smirked up at him, kneeling obediently and getting to work undoing Loki's pants.

Meanwhile, Steve was gasping breathlessly, leaning heavily back into the wall as Tony's hands and mouth drove him slowly insane.

Having stripped Steve of his clothes, Tony had explored his way down his chest with his tongue, getting ever lower until he was kneeling before him, smirking up at Steve in silent inquiry.

Heavy-lidded, Steve glanced over to see where Loki had gone only to see him being pleasured by his own clone. Swallowing hard at the sight, Steve's hand found Tony's hair, grasping it roughly.

Tony took that as an invitation to continue and Steve gasped as he was suddenly enveloped by Tony's hot mouth, his skilled tongue swirling around him. Tony rested his hands on Steve's hips, holding him still as he took in as much of Steve's length as he could.

Steve controlled his hips with an effort, tightening his grip on Tony's hair painfully as Tony did something clever with his tongue. "I'm going to-" he began, and then moaned in loss as Tony pulled off.

"Not yet," Tony said, smiling apologetically and wiping his mouth. Steve nodded, watching impatiently as Tony began taking his own clothes off.

Loki, glancing over at them, decided he wanted to be included too. Dismissing his clone, he appeared next to Tony. "Allow me," he offered smoothly, vanishing both his own clothing and Tony's with a thought.

Tony looked down at himself in surprise, then froze when he felt lips on his shoulder, a gentle scrape of teeth along the bone. Just as he was about to reprimand Loki with a few choice words, Steve was kissing him rather fiercely.

He was caught in limbo between the two mouths, Loki moving along his shoulder to kiss and bite at his neck. It was at that moment that Tony decided he didn't care anymore. He'd never been great at being the responsible one anyway, and Loki didn't seem to be overtly threatening. Besides his mouth felt _really _good along his throat. As Steve broke away to breathe, Tony lifted his head with a groan, allowing Loki greater access to his throat.

Loki immediately latched into his pulse point, sucking and biting hungrily.

Tony's hand came up to tangle itself in Loki's hair, tightening in warning as Loki bit him particularly hard.

Loki chuckled darkly, pressing a small kiss to the bite before moving up to his mouth. This time Tony did not resist the kiss but opened his mouth willingly.

Steve watched in fascination as the kiss became an aggressive tangle of tongues and teeth, neither participant willing to surrender to the other. Feeling rather left out, Steve's mind returned to more practical measures. He looked around, wondering where the best place to find lube would be.

"Tony?" he asked hesitantly, just as Tony pulled back to breathe, looking rather dazed.

"Yeah?"

"Where do you keep the-" Steve broke off as Loki wordlessly handed him a tube summoned seemingly from nowhere.

Tony laughed breathlessly against Loki's neck. "You're useful, we should keep you around," he murmured against his skin.

Loki rolled his eyes, "I'm so glad you approve." He held Tony still as Steve approached, watching as he began preparing him. As he stiffened in surprise at the sudden intrusion, Loki soothed him with a slow and very distracting kiss, feeling Tony relax against him.

Before long, Steve was able to easily move three well-lubricated fingers inside Tony. He curled his fingers experimentally, searching for his prostate, knowing he'd found it at once as Tony's back arched with a pleasured gasp.

Kissing Tony once more and swallowing his moans, Loki pulled away and circled around until he was behind Steve. Once Steve had lubricated himself, Loki took the tube from him and began swiftly preparing Steve himself.

Steve rested his hands on Tony's hips, tightening his grip in warning. "You ready, Tony?"

"Yeah," Tony answered, bracing himself against the wall. "Do it, Rogers."

Steve carefully slid himself in, then gasped in surprise as Loki did the same to him.

"You could have warned me" he bit out.

"I apologise," Loki purred, not sounding sorry at all. He set a slow, deep pace, Steve matching it, and Tony's hips snapping up to meet him, all three bodies moving in tandem.

"Faster," Tony hissed, so Loki set a faster, harder pace, Steve copying it, reaching down to grip Tony's erection and pump it in time to his thrusts.

Tony came first with a cry in Steve's calloused grip, gasping for breath and leaning against the wall as he recovered. Steve and Tony both outlasted him by several moments due to their superior endurance.

Steve was next, spine arching as he climaxed, shuddering with release. Loki soon followed, muffling his cries against Steve's broad back.

They both carefully pulled out, Loki cleaning all three of them up with magic, still panting slightly.

Tony rested his back against the wall and slid to the floor, watching as Steve did the same next to him. He curled into his side, resting his head on his shoulder and smiling as a strong arm wrapped around him and pulled him close.

Loki watched the couple, feeling a prickle of discomfort. He felt as though he was intruding and disliked how much that bothered him. Dressing himself, he was about to leave until he heard Tony's voice.

"Hey Loki."

Loki turned to face him, eyebrow raised questioningly.

Tony smirked at him, still slightly euphoric in the afterglow. "Next time I'm topping."

"Don't be ridiculous," Loki snarled. _The gall of this mortal!_ "There won't be a next time. I have satisfied my curiosity, now I will take my leave."

He disappeared, a plume of emerald smoke marking where he'd stood moments ago.

Tony and Steve exchanged glances.

"His loss," Tony declared, stretching luxuriously.

"Bedtime I think," Steve decided, pulling Tony up to stand.

Loki sat in his lair, reviewing the night's activities. Rogers arriving hadn't been part of the plan but who was he to refuse such a fine specimen of masculinity? It was for science, he told himself. And alright, he _may_ have lowered Steve's inhibitions slightly, but not by much. Just enough for his brain to agree with his body.

As for Tony, _well_. The man had enough arrogance to rival Loki's own, though Loki supposed he knew that already. Still, he had a very clever tongue and skilled hands, this Loki could appreciate.

When Tony had come over to where he had been thoroughly exploring Steve against the wall, he had whispered in his ear to "go fuck yourself, Steve is _mine_." Loki had been impressed by the fierceness of the statement and had moved aside.

He could never have predicted that he would actually end up fucking himself though, or being sucked off by himself anyway.

Loki's lips curved at the irony. Perhaps that was the most valuable lesson he had learnt, he thought, conjuring a simulacrum and smirking as it knelt before him.

Why rely on others when you can rely on yourself?

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A/N: If you are reading this then you managed to make it to the end and for that I applaud you. Thank you, kind reader.


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